An electronic device generally has a power supply for driving a load circuit. In recent years, many electronic devices (typically, a television receiver) each include a main power supply circuit supplying a power supply voltage to each part of the device body, and a standby power supply circuit for operating a light-receiving circuit, a microcomputer (hereinafter also referred to as a mi-con) or the like of a remote controller.
The standby power supply circuit supplies a power supply voltage to the light-receiving circuit, the microcomputer or the like of the remote controller even when a main power supply circuit is in the OFF state. For example, when the remote controller instructs the light-receiving circuit to turn the power on, the main power supply circuit is operated under control of the microcomputer. On the other hand, when the remote controller instructs the light-receiving circuit to turn the power off, the main power supply circuit is stopped under control of the microcomputer. When the electronic device is in the standby mode, the device body consumes less power. When the main power supply circuit is stopped, the loss of the main power supply circuit is suppressed. This allows a reduction in the standby power of the electronic device.
For example, Japanese Patent Laying-Open No. 2004-23894 (Patent Literature 1) discloses an electronic device provided with a main power supply circuit and a standby power supply circuit. The standby power supply circuit is configured of a switching power supply. This switching power supply includes means for detecting a surge voltage generated at the time when AC power is turned on. When this detection means detects a surge voltage, a switching control circuit inhibits the operation of a MOSFET (Metal Oxide Semiconductor Field Effect Transistor) serving as a switching element.